The present invention relates to methods, and compositions for treating human patterned alopecia, also called androgenic alopecia involving the use of minoxidil (or related compounds) and antiinflammatory agents.
Dermatologists recognize many different types of hair loss, the most common by far being "androgenic alopecia" wherein human males begin losing scalp hair at the temples and on the crown of the head in early adult life. This type of hair loss is more common and more severe in males, hence its common name "male pattern baldness". However, similar patterned baldness occurs in women, though it progresses more slowly and does not reach the end stage of complete denudation. An effective treatment for these and related conditions has long been sought.
There are two types of hair follicles which produce either "terminal hairs" or "vellus hairs". Terminal hairs are coarse, pigmented, long hairs in which the bulb of the follicle is situated deep in the skin, usually in the subcutaneous tissue. Vellus hairs, on the other hand, are fine, thin, non-pigmented short hairs whose bulbs are located superficially in the upper dermis. In patterned alopecia, follicles which produce terminal hairs are gradually converted to vellus ones through a miniaturization process.
Along with this progressive involution there inevitably occurs changes in the proportion of hairs in the various phases of the hair cycle. All follicles pass through a life cycle that includes three phases, namely, (1) anagen (2) catagen and (3) telogen. The anagen phase is the period of active hair growth and, on the scalp generally lasts from 3-6 years. Catagen is a short transitional phase when the follicle contracts in preparation for a resting period. It lasts a couple of weeks. In telogen, the follicle is in a resting phase where all growth ceases and the hair becomes short "club" hairs. When a new cycle begins, the club hair is shed. Telogen scalp hairs are relatively short-lived, about three to four months.
Normally, approximately 90% of scalp hairs are in the anagen phase, less than 1% in catagen and the remainder in telogen. With the onset of patterned baldness, a successively greater proportion of hairs are in the telogen phase, with correspondingly fewer in the active growth anagen phase.
Additionally, there may be some actual loss of hair follicles but this is limited to the last final phase. For the most part, the visible diminution in the bulk of hair is due to the miniaturization of the follicles. In completely bald areas, all the follicles are in the vellus phase producing ugly fine, short, non-pigmented hairs which are cosmetically useless. It may take 20 to 30 years for the distinctly anagen follicles on the crown to become transformed into a uniform population of vellus follicles.
Patterned baldness is sometimes called androgenic alopecia because male hormones are necessary for its development. It does not occur before adolescence, nor in castrates. Attempts to prevent alopecia by hormonal treatments by using anti-androgens or female hormones have failed. A hereditary component is also recognized since patterned alopecia runs in families. Despite intensive investigation, the mechanism whereby terminal follicles convert to vellus ones is unknown.
At the present time, one effective treatment for patterned alopecia is hair transplantation. Plugs of hair-bearing skin from the back of the scalp are transplanted into the bald areas. The procedure is costly and painful. Hundreds of plugs must be transplanted to create an appearance of hairiness. It is impossible to obtain anything near the original density of terminal hair.
Many other approaches for creating or reversing patterned alopecia have been tried including ultra-violet radiation, massage, chemical irritation and innumerable natural products and herbs. None of these has been generally accepted as effective.
Drugs offer a more rational approach--though for the most part have been designed to interfere with drug metabolism. The results have been poor to date. In Europe, a schedule of estrogens and antiandrogens have been administered orally to balding females with inconsistent results and with obvious limitations.
The androgenic hormone testosterone has been shown to stimulate hair growth when injected into the beard and pubic regions of adult females. Also, topical application to the armpit causes increased hair growth in aged persons. Nonetheless, topical application of testosterone has not been able to grow hair in balding individuals. Indeed, high doses of oral testosterone can induce patterned alopecia.
The topical application of minoxidil is currently the most effective therapy for patterned alopecia. Minoxidil is a well-known pharmaceutical agent marketed by the Upjohn Company in the form of LONITEN.RTM. tablets for the treatment of hypertension. Numerous investigators have demonstrated that it can stimulate visible hair growth in a majority of balding subjects. The structure and use of this compound is described in U.S. Pat. Nos. 4,139,619 and 4,596,812. This compound has varying degrees of efficacy for moderating androgenic alopecia, depending on the degree of baldness, its duration, the age of the patient and, of course, on the concentration of the drug in an appropriate vehicle.
The present invention provides a novel, non-obvious and effective treatment for patterned male and female alopecia.